The disparity between rich and poor in children's tooth decay doubled in the past two decades at the same time that dental care utilization increased among low income children. Dental care does not eliminate income disparities because it does not target upstream risk factors that disproportionately affect low income groups. The solution requires population-based interventions that preferentially benefit children at highest risk. This proposal draws together investigators from social- and oral epidemiology, health economics, political science, and nutrition to partner with community representatives tapping into experiences of The Pew Charitable Trusts, the Association of State and Territorial Dental Directors and a local Community Advisory Board of influential community stakeholders. At the crux of the project is the idea that state-to-state variation in policy adoption acts as a natural experiment. The overall objective is to identify state policies that influence social, economic and behavioral determinants of oral health disparities and community action to support sustainable reduction in disparities. Dental caries is the primary disease of interest. Secondary outcomes are serum cotinine and oral human papilloma virus (HPV) infection as surrogate markers of early risk of periodontitis and oral cancer. Time series data will be collected on policy adoption for states and, where applicable, counties for all years available. Policy activities prioritize six primary intervention themes: community water fluoridation; restricted soda consumption; tobacco control; HPV vaccine promotion; children's dental insurance coverage; and welfare. The first aim of phase one is to compile a time-series state policy database on: cigarette excise tax; bans/tax on soda; HPV vaccine promotion, minimum wage, earned income tax credit (EITC), and health plans with pediatric dental coverage. Community water fluoridation will be collected at the county level. Aim 2 will enrich the database with time-series intermediary variables at multiple levels of influence between policy and oral health outcomes. For example, state policy influences communities (e.g. per capita sales of cigarettes and soda). The effect flows to behavior (e.g. soda intake, smoking), nutrition (e.g. daily total energy, total nutrient intake); and becomes embedded in biology (e.g. serum cotinine). The database will be merged into the 1988- 2014 National Health and Nutrition Examination Survey (NHANES) cycles using restricted access geocodes. The objective of phase two (years 3-4) is to examine the relationship between state policy, intermediate variables and the individual unit-level outcomes measured in children aged 2 to 21 years in NHANES. Aim 1 will quantify the relationship between fluoridated water and disparities in dental caries. Aim 2 will quantify the relationship between policies governing the sale of soda, consumption, and disparities in dental caries. Aim 3 will quantify the relationship between tobacco regulation and disparities in serum cotinine. Aim 4 will quantify the relationship between HPV vaccine promotion and disparities in oral HPV infection. Aim 5 will explore effects of EITC effects on in income disparities in dental care and oral health outcomes.